Looper housing arrangement



United States Patent Inventor Appl. No.

Filed Patented Assignec Priority Josef Rouha,

Boskovice, Czechoslovakia Sept. 13, 1968 Sept. 29, 1970 Elitex, Zavody Textilniho Strojirenstvi Generalni Reditelstvio, Liberec, Czechoslovakia Sept. 14, 1967 Cmechoslovakia LOOPER HOUSING ARRANGEMENT 13 Claims, 8 Drawing Figs.

U.S. Cl. 112/258, 1 12/23 1 int. Cl D05b 75/00 Field of Search 1 12/231, 258, 259. 260

[56] References Cited UNITED STATES PATENTS 2,318,836 5/1943 Clayton 112/258 2,424,025 7/1947 Gegauf 112/260 3,066,627 12/1962 Schlosser et al. 1 12/260 Primary ExaminerA1fred R. Guest Attorney-Michael S. Striker ABSTRACT: A cover normally closes the open end ofa tubular housing portion of a sewing machine in which a looper or shuttle with an exchangeable bobbin is mounted. For exchange of the bobbin, it is necessary to move the cover away from the housing end portion against the action of a spring, and then to turn the cover in a transverse plane to a position in which the open end of the housing portion is uncovered and access to the bobbin is provided. Blocking means prevent the turning of the cover in the normal closing position.

Patented Sept. 29, 1970 Sheet 1 of2 INVENTOR Ina-F- Quay/ v rizlr,

ATTORN EY Patented sq. 29, 1970 Sheet 2 of 2 fig. 2a 2 Z'i'g. 2b

JNVENTOR JDSEF 000164 LOOPER HOUSING ARRANGEMENT BACKGROUND OF THE INVENTION In sewing machines, the needle providing the upper thread cooperates with a shuttle or looper supporting an exchangeable bobbin for the lower thread. The capacity of the bobbin is limited, and it is necessary to remove empty bobbins whose thread has been exhausted, and to replace it with a bobbin with a new supply of thread wound thereon. During a working shift of a sewing machine operator, the time spent in exchanging bobbins is not negligible since in high speed sewing machines, the thread supply on the bobbin is exhausted in about five minutes so that ninety bobbin exchanges are required within a working shift of eight hours.

Special sewing machines are known for sewing tubular work pieces, such as stockings. Sewing machines of this type have a tubular housing arm in whose end portion the shuttle or looper with the bobbin is located. For safety reasons, it is necessary to cover the open end of the housing arm so thataccidental insertion of the operators finger into the sewing region is prevented, while at the same time foreign objects are kept out of the space in which the shuttle or looper cooperates with the needle. Therefore, each exchange of a bobbin requires the removal of the cover, and its return to the normal closing position. Since the cover vibrates during operation of the sewing machine, it must be attached in such a manner that it does not accidentally open.

In accordance with one construction of the prior art, a cover is moved in longitudinal direction of the housing arm from a closing position to an open position along a guide which occasionally causes jamming when little play is provided, and results in opening of the cover by vibration if ample play is provided.

Another construction according to the prior art provides a cover with bayonet slots cooperating with screw heads so that the cover can be entirely removed after turning a small angle. The disadvantage of this construction is that the screws have to be loosened before the cover is turned and tightened after replacement of the same. It has been proposed to provide springs for urging the cover against the screw heads, but during operation of the sewing machine, vibrations tend to open the cover. Furthermore, the detached cover must be held, or placed on a table so that time is lost.

In accordance with another construction of the prior art, a cover is connected by a hinge to the open housing arm, and can be angularly turned to an open position against the action of a spring. A disadvantage of this arrangement is that the hinge projects outwardly from the housing arm taking up valuable space, and furthermore one hand of the operator is occu' pied by holding the cover in the tilted position to prevent closing of the cover by the tensioned spring while the bobbin is being exchanged.

ln constructing a cover for the housing arm, it must be taken into consideration that available space in the longitudinal direction of the housing arm, is limited by the needle bar assembly and by the presser bar assembly.

SUMMARY OF THE INVENTION It is one object of the invention to overcome the disadvantages of the prior art, and to provide a looper housing arrangement with a cover which takes up little space, and can be easily moved between a closing position, and an open position in which exchange of the bobbin is possible.

Another object of the invention is to provide a cover for the space in which a looper or shuttle with a bobbin is mounted, and attach the cover in such a way that it will not open due to vibrations of the sewing machine.

Another object of the invention is to provide a cover for a housing arm which can be operated by an inexperienced and unskilled operator.

Another object of the invention is to provide a cover movable between a closing position and an open position, and remaining attached to the housing arm in both positions so that the operator has both hands free after opening of the cover.

Another object of the invention is to provide a housing arm with a cover which can be opened and closed without requiring the hands of the operator to pass the area of the needle bar assembly.

Another object of the invention is to provide a housing arm of a sewing machine with a cover which can be opened without tools.

With these objects in view, the present invention relates to a looper housing arrangement which comprises a tubular open housing end portion of the housing arm of a sewing machine in which a looper and an exchangeable bobbin are mounted. The term looper" is used in the present application to describe any shuttle, or rotary or oscillatory hook which supports an exchangeable bobbin with a thread wound thereon.

One embodiment of the invention comprises cover means having a normal closing position for closing the open end of the housing end portion, and being preferably urged by spring means to assume the closing position; mounting means on the housing end portion supporting the cover means for turning movement about an axis spaced from the axis of the tubular housing end portion, and for axial movement from the closing position to a displaced position axially spaced from the open end of the housing end portion; and blocking means blocking turning movement of the cover means in the closing position, and permitting turning movement of the cover means in the displaced position to an open position uncovering the open end of the housing end portion for exchange of the bobbin.

The cover means includes a cover portion and a connecting pin or sleeve perpendicularly projecting from the cover portion and supported by the mounting means for turning movement with the cover portion, and for axial sliding movement with the cover portion. If a connecting pin is used, it is supported in a bearing bore in a wall portion of the housing end portion, and if the connecting member is a sleeve, it is supported on a pin secured to the housing end portion and projecting into the sleeve. In both constructions, the axial movement of the cover means away from the housing end portion is limited so that the cover means stops in the displaced position in which turning movement to the open position is possible.

During movement of the cover means from the closing posi tion to the displaced position, the cover means cannot be turned, and in the displaced position, it can be turned an angle of preferably to the open position, while remaining connected with the housing end portion by the connecting-pin or connecting sleeve.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRlPTlON OF THE DRAWlNG FIG. 1a is a fragmentary axial sectional view taken on line la-la in H6. 1c, and illustrating the mounting of a cover means on the tubular end portion of a sewing machine arm;

FIG. lb is a fragmentary perspective view illustrating the cover means of the embodiment of FIG. la;

FIG. lc is a fragmentary, partly exploded, perspective view of the housing end portion of the embodiment of HG. 1;

FIG. 1d is a bottom view of the arrangement shown in H0. la;

' FIG. 2a is a fragmentary axial sectional view illustrating another embodiment of the invention;

FIG. 2b is a fragmentary, partly exploded, perspective view of cover means used in the embodiment of HG. 2a;

FIG. 2:: is a fragmentary perspective view of the housing en portion; and

FIG. 2d is a fragmentary axial sectional view illustrating a detail of FIG. 2a on a larger scale.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. la-ld, the housing arm 4 of a sewing machine has a tubular housing end portion 5 to whose end face an annular end member 6 is secured by screws 7 engaging threaded bores in the housing end portion 5. A throat plate 3 is secured to the housing end portion 5 and projects in axial direction beyond the end face of member 6. A shaft 5a is mounted in the housing arm 4 of the sewing machine and projects into the housing end portion 5 for driving a shuttle or looper supporting a bobbin B and being located in the housing end portion 5.

The open end of housing end portion 5 and member 6 can be closed by a cover 1 which includes a segment shaped plate la, a flange 1c, and a connecting pin 2 perpendicularly projecting from cover plate la. Cover 1 can be placed in the position shown in FIGS. la and Id in which its flange lc fits on the marginal rim formed by the outer peripheral surfaces of housing end portion 5 and member 6. The edge lb is formed of straight edges of cover plate la and flange 1c and fits the bottom face of throat plate 3 in the closing position shown in FIGS. la and 1d in which the open end of the housing end portion 5 is closed by cover I.

In this position, the connecting pin 2 of cover 1 projects through a cutout 6a in member 6 into a bearing bore 8 in the wall of housing end portion 5 so that pin 2 is slidable in axial direction of the bearing bore 8, and is also turnable about an axis parallel to the longitudinal axis of the tubular housing end portion and of shaft 5a. However, turning of connecting pin 2 is not possible in the closing position shown in FIG. la since the edge lb of cover I abuts throat plate 3, and since flange 1c extends about a corresponding peripheral portion of member 6. In the event that member 6 and flange lc are omitted, turning of cover 1 is prevented in the closing position by abutment of the edge lb on the bottom face of throat plate 3 which may be considered a stop means serving this purpose.

The end portion of connecting pin 2 projects out of bearing bore 8 into a recess 11 in the wall of the housing end portion 5. The end portion 2b of pin 2 is formed with an annular groove 2a in which a split ring 9 is mounted to form an abutment on which one end ofa coil spring 10 surrounding pin 2 abuts. The other end of'the coil spring 10 abuts a face 11b of recess ll. The pressure of spring 10 urges pin 2 to the right as viewed in FIGS. la and Id, so that cover 1 is urged into the closing position in which it cannot be turned.

When a bobbin B is to be exchanged or removed, it is necessary to open cover I. The operator inserts a finger into recess 11 and presses pin 9 toward the left against the action of spring 10 so that flange 10 moves in axial direction away from member 6 and housing end portion 5 until separated from the same, while at the same time, edge lb moves along throat plate 3 until reaching the end of the same. In this axially displaced position, not shown, the operator can grip cover 1 and turn the same with pin 2 in bearing bore 8 to an open position in which the open end of the tubular housing end portion 5 is fully exposed which requires a turning of cover 1 over an angle of 180. 7

This operation can be efficiently carried out by pressing against the end of pin 2 by the left thumb, and after movement of the cover I to the axially dis r iaced position in which it can be turned, pressing with the index finger of the same hand against flange lc of cover 2 anti? cover 1 has been turned to the open position. Thereupon, pin 2 is released by the thumb, and the cover is retracted by spring 10 to a position in which its flange lc abuts the lower portion of member 6 under the action of spring 10. Both hands of the operator are now free for removing the bobbin from the interior of the tubular housing portion 5.

For returning cover I to its normal closing position, the end 2b of pin 2 is pressed in the direction ofthe arrow F so that pin 2 with cover 1 moves a small distance and the edge of flange is no longer abuts the front surface of member 6. Consequently, cover I can be freely turned with pin 2 in bearing bore 8 until flange 1c registers with the outer periphery of member 6, and edge lb registers with the bottom face of throat plate 3. When pin 2b is now released, spring 10 urges pin 2 with cover 1 to the right as viewed in the drawing so that cover 1 moves in axial direction to the closing position, with flange lc sliding on the peripheral surface of member 6, and edge lb sliding on the bottom surface of throat plate 3.

The second embodiment of the invention illustrated in FIGS. 2a, 2b, 2c and 2d operates on the same principle. The housing arm 24 terminates in a tubular housing end portion 25 whose marginal rim is partly formed by an annular member 26 secured by screws 27 to the end face of the housing end wall portion 25. The upper peripheral portions of members 25 and 26 are flattened, and a throat plate 23 is mounted thereon. The cover 20 has a segment shaped cover plate 20a with a part-circular flange 20c. Cover plate 20a and flange 20c are cut off and bounded by a straight U-shaped edge 20b so that in the closed position of cover 20, flange 20c embraces a peripheral portion of member 26, and edge 20b abuts the bottom face of throat plate 23, whereby any turning of cover 20 on the housing end portion 25 and member 26 is blocked. As in the embodiment of FIGS. la-ld, flange 200 could be omitted since throat plate 23 serves as the stop means blocking turning movement of cover 20. If a circular flange 20c were provided, and stop plate 23 accordingly modified, turning of the cover 20 about a circular wall of housing end portion 25 would not be possible since turning movement of cover 20 about the axis of the housing end portion is prevented in the embodiment of FIG. la-ld by pin 2 and in the embodiment of FIG. 2a-2d by a connecting sleeve 22 secured to cover plate 20a and projecting into a semi-cylindrical recess 25a in the wall of housing end portion 25. Sleeve 22 projects perpendicularly from cover plate 20a and is secured to the same by welding in a position located directly adjacent the flange 20c.

Sleeve 22 has an opening 21 in the plane of cover plate 20a, and an inner flange at its other end forming an annular abutment 22a.

A pin 31 has a head 31a located in the opening 21 of sleeve 22, and a threaded stem portion 31b threaded into a threaded bore 32 in a wall of housing end portion 25. A coil spring 30 surrounds pin 31 within sleeve 22 and has ends 30a and 30b respectively abutting the head 31a and the abutment shoulder 22a of sleeve 22 so that sleeve 22 is urged toward the right in the part-cylindrical bearing recess 25a until cover 20 is in the closing position in which flange 200 extends about the periphery of member 26.

Although sleeve 22 is turnable about pin 31 and in part-circular bearing recess 25a, turning of cover 20 in the closing position is prevented by throat plate 23 acting as a stop, and by flange 20c. If throat plate 23 is differently placed, turning of cover plate 20 about the main axis of the tubular housing end portion is not possible due to the eccentric position of sleeve 22 in bearing recess 25a. Due to the provision of both a projecting throat plate 23 and a flange 20c, the play of the cover 20 is very limited and dust is prevented from entering into the interior of the housing end portion 25. However, a minor angular displacement of cover 20 due to play would not detrimentally influence the operation of the device.

When a bobbin in the tubular housing portion 25 is empty, the operator grips cover 20 and pulls the same against the action of spring 30 in the direction opposite to arrow H in FIG. 2a until flange 20c separates from member 26, and edge 20b separates from throat plate 23 in axial direction. In this displaced position, not shown, cover 20 can be turned about the axis defined by part-cylindrical bearing recess 25a and by sleeve 22 an angle of which completely exposes the open end of the tubular housing end portion 25 surrounded by member 26. When cover 20 is released by the operator in the open position, spring 30 urges the edge of flange 206 against the lower portion of the end face of member 26 so that cover 20 remains in the open position and need not be removed. After exchange of the bobbin, cover 20 is first moved away from member 26,- and then turned with sleeve 22 in part-cylindrical recess 25a to a position spaced from member 26, but aligned with the same whereupon release of the cover 20 by the operator will cause spring 30 to move cover 20 in the direction of the arrow H to the closing position in which flange 200 extends about the periphery of member 26, and edge 20b abuts the bottom face of throat plate 23.

The movement of cover plate 20 away from a tubular housing end portion 25 is limited in a position in which spring 30 is fully compressed between head 31a and abutment flange 22a. ln this position, not shown, cover 20 can be turned to the open position. Similarly, in the embodiment of FIG. la-ld, cover 1 can be moved in axial direction away from the tubular housing end portion 5 a limited distance until coil spring is fully compressed between split ring 9 and face 11b of recess 1 l.

The springs 10 and 30 constitute resilient means for holding the cover in the closed position during sewing operations so that the cover cannot be substantially displaced by vibrations. It is possible to provide other resilient means serving the same purpose, for example spring catches on cover snapping into corresponding recesses in the periphery of member 26.

Resilient means of any type will yield when manual force is applied to cover 1 or cover 20 to move the same out of the closing position to the displaced position, not shown, in which turning to the open position about connecting member 2 or connecting member 22 is possible.

lt will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of housing arrangements for loopers and shuttles differing from the types described above.

While the invention has been illustrated and described as embodied in a housing arrangement in which the tubular housing end portion of a sewing machine is closed by an axially shiftable cover turnable about an eccentric axis, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

1 claim:

1. Looper housing arrangement, comprising, in combination, a sewing machine housing having a tubular housing wall end portion with an open end bounded by a marginal rim, and a longitudinal first axis extending through said open end; means in said tubular housing wall end portion for mounting therein a looper and an exchangeable bobbin; cover means having a normal closing position transverse to said first axis and being in contact with said marginal rim for closing said open end of said tubular housing wall end portion; mounting means on said housing supporting said cover means for turning movement about a second axis spaced from said first axis, and for movement in the direction of said first axis from said closing position to a displaced position spaced from said marginal rim of said housing wall end portionand from said open end in the direction of said first axis; and blocking means for blocking turning movement of said cover means about said second axis in said closing position so that said cover means can be turned only from said displaced position about said second axis to an open position uncovering said end of said housing wall end portion for the exchange of the bobbin, and cannot turn and open in said closing position.

2. Looper housing arrangement, comprising, in combination, a tubular open sewing machine housing end portion having a firstaxis and a marginal wall portion; means in said housing end portion for mounting therein a looper and an exchangeable bobbin; cover means having a normal closing position for closing said. housing end portion; mounting means formed by said marginal wall portion supporting said cover means for turning movement about a second axis spaced from said first axis, and for movement in the direction of said second axis from said closed position to a displaced position axially spaced from said housing end portion, said second axis being located in said marginal wall portion and being parallel to said first axis; and blocking means blocking turning movement of said cover means about said second axis in said closing position so that said cover means can be turned in a plane perpendicular to said first and second axes only from said displaced position about said second axis to an open position uncovering said housing end portion for exchange of the bobbin, and cannot turn and open in said closing position.

3. Looper housing arrangement as claimed in claim 1 and comprising resilient means for holding said cover means in said closing position during sewing operations so that manual force is required for moving said cover means to said displaced position.

4. Looper housing arrangement as claimed in claim 1 wherein said blocking means include a marginal edge portion of said housing end wall portion; and wherein said cover means has a flange fitting on said edge portion in said closing position so that the same blocks turning movement of said cover means, said flange being slidable on said edge portion in axial direction until separating from the same in said displaced position of said cover means.

5. Looper housing arrangement as claimed in claim 1 wherein said blocking means include a stop means projecting in axial direction from said housing end portion; and wherein said cover means abuts said stop means in said closing position so that turning movement of said cover means is blocked in said closing position whereas said cover means in said displaced position passes said stop means when moving to said open position.

6. Looper housing arrangement as claimed in claim 1 wherein said mounting means includes means for stopping axial movement of said cover means in said displaced position.

7. Looper housing arrangement as claimed in claim 1 wherein said cover means includes a cover portion and a connecting member secured to said cover portion and perpendicularly projecting from the same in the direction of said second axis; and wherein said mounting means support said connecting member on said housing end portion for turning movement with said cover portion about said second axis, and for axial sliding movement with said cover portion.

8. Looper housing arrangement as claimed in claim 7 wherein said connecting member includes a pin; wherein said mounting means includes a wall portion of said housing end portion formed with a bearing bore having said second axis, said pin being mounted for turning and axial sliding movement in said bearing bore, and spring means abutting said pin and said wall portion for urging said pin with said cover portion into closing position.

9. Looper housing arrangement as claimed in claim 8 wherein said wall portion has a recess into which one end of said bearing bore opens so that the end portion of said pin remote from said cover portion projects from said bearing bore into said recess and is accessible for manual operation; and wherein said spring means is located in said recess so that by finger pressure on said end portion of said pin in said recess, said cover means is moved against the action of said spring means from said closing position to said displaced position and can be manually turned to said open position.

10. Looper housing arrangement as claimed in claim 7 wherein said connecting member includes a sleeve coaxial with said second axis and having an abutment on the end thereof remote from said cover portion; wherein said mounting means includes a wall portion of said housing end portion formed with a bearing recess receiving said sleeve, and a pin coaxial with said second axis projecting into said sleeve and having an abutment cooperating with said abutment of said sleeve in said displaced position of said cover means to limit axial movement of the same away from said housing end portion.

l3. Looper housing arrangement as claimed in claim I wherein said marginal rim of said tubular housing wall end portion is formed with an opening concentric with said second axis; wherein said cover means includes a cover portion, and a connecting member at least partly located in said opening of said annular rim supported by said mounting means; and wherein said cover portion is spaced from said marginal rim in the direction of said first axis in said displaced position of said cover means. 

